how many qubits are needed - BSI report 2022 (Re: deflating heffalumps)

[Bruce Walzer]

On Tue, Mar 11, 2025 at 09:09:08AM +0100, Bernhard Reiter via Gnupg-users wrote:
[...]
> Quantum-safe cryptography – fundamentals, current developments and 
> recommendations, BSI
> from 18.05.2022 
> https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Publications/Brochure/quantum-safe-cryptography.html?nn=916626
> 
> and the referenced study, it is a few years old now, but it explains the 
> principles as far as I understand it.

Three years old in particular. That was a time when whe quantum threat
to crytpography seemed a lot more real. Now it is understood that
error correction will not be possibly useful until the noise
performance of physical qubits can be improved by a factor of 1-2
orders of magnitude. Since no one knows how to do that, we are back in
the position where some sort of fundamental breakthrough will be
required to progress further. So the predictions in the linked file
are invalid. Progress could come tomorrow or never.

Bruce